linux-kernel - Re: [BUGFIX] PM: Fix active child counting when disabled and forbidden

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1353027296.7176.312.camel@yhuang-dev>
Date:	Fri, 16 Nov 2012 08:54:56 +0800
From:	Huang Ying <ying.huang@...el.com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
Cc:	Alan Stern <stern@...land.harvard.edu>,
	linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [BUGFIX] PM: Fix active child counting when disabled and
 forbidden

On Fri, 2012-11-16 at 01:55 +0100, Rafael J. Wysocki wrote:
> On Friday, November 16, 2012 01:44:00 AM Rafael J. Wysocki wrote:
> > On Friday, November 16, 2012 08:36:14 AM Huang Ying wrote:
> > > On Thu, 2012-11-15 at 10:51 +0100, Rafael J. Wysocki wrote:
> 
> [...]
> 
> > > 
> > > For this situation, if user "echo auto > .../power/control" for the
> > > device, the runtime PM callbacks of device will be called.  I think that
> > > is not intended.  So I think it is better to use some kind of flag or
> > > state for that.
> > 
> > I'm not sure what situation exactly you have in mind.  Care to give an
> > exact scenario?
> 
> Ah, I see.  When we've just called drv->remove(), there is a window in
> which user space may cause the driver's runtime PM callbacks to be
> executed by changing its attribute to "auto".
> 
> So perhaps we should check pci_dev->driver rather than pci_dev->dev.driver
> in the runtime PM callbacks?  With a few more changes that should allow us
> to close that race.

Yes.  And I think, with pci_dev->driver (after some changes suggested by
Alan), we need not to use pm_runtime_get/put_skip_callbacks().

Best Regards,
Huang Ying


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/